If your still looking for more & your a programmer then you should find the following books worth a read (if not already found) -
Programming Arduino Getting Started with Sketcheshttp://www.amazon.com/Programming-Arduino-Getting-Started-Sketches/dp/0071784225/ref=sr_1_1?s=books&ie=UTF8&qid=1391243884&sr=1-1&keywords=Programming+Arduino+-
Although most of this may be a bit basic for you, and by now you may have covered most of it - it at least gives a good overall intro to programming the Arduino, touches writing to various memory areas & some useful tips .
However the latest book
Programming Arduino Next Steps: Going Further with Sketcheshttp://www.amazon.com/Programming-Arduino-Next-Steps-Sketches/dp/0071830251/ref=pd_sim_b_1
Does go into a lot more depth, especially the various ways of serial interfacing with the Arduino., and might be of more interest.
Hope this helps